spec

Software for Diffraction

3.9. - Scan Macros



The following sections summarize the usage of the standard scans in spec. This discussion is followed by a description of macros to customize the scan output sent to the printer and data file. Refer 3.12 for a detailed discussion of a single-motor scan.

All the scans use the same basic invocation syntax. For example, the single motor, absolute-position scan is invoked as
ascan  motor  start  finish  intervals  time
The range of a scan is specified by the starting position start, the final position finish and the number of intervals intervals of the scanned parameters. Thus
ascan  tth  26  28  20  60
would start with the tth motor at 26°, and move the motor to 28°, using 20 intervals of 0.1°. The total number of points scanned is one more than the number of intervals, in this case, 21 points. The time per point time, if a positive number, indicates counting to seconds. In the above example, each point takes 60 seconds. Using a negative time indicates counting to monitor counts.